Beginning balance for bank account is wrong. How do I fix this?

We appreciate you for posting here in the Community space. Let me help you regarding your beginning balance issue in QuickBooks Online (QBO).

The beginning balance is the starting point for accounts in QuickBooks. Since it seems incorrect on your side, follow the steps below to fix this.

The first step is to review the original opening balance.
Make sure to check your original opening balance to see some discrepancies. Correcting the opening balance should also fix your beginning balance issues.

See your bank statement as the next step.
Reconcile the correct amount for the correct month. Here's how:

1. In Transactions, click Reconcile.
2. From the Account dropdown, select the account you want to reconcile.

After that, match and categorize downloaded transactions.
Match and categorize your downloaded transactions before you reconcile, if your account is connected to online banking. Categorize everything to have your final correct beginning balance.

See any discrepancy reports.
You'll receive a message before reconciling if anyone changes and takes effect in your beginning balance:

1. To open the discrepancy report, click the We can help you fix it link.

1. Thoroughly review the reported discrepancy.
2. Once done, edit it if needed.

Review each transaction in the report one at a time before making corrections.

1. Click View and see the history of the changes transaction.
2. See the Change Type column. You can see here what needs to be changed.

To edit the Change Type column, visit this link and go to Step 4 as a guide to help you how: Fix issues for accounts you've reconciled in the past in QuickBooks Online.

Moreover, you may also see this article if you want to fix reconciled mistakes after reconciling an account in QBO: Undo or remove transactions from reconciliations in QuickBooks Online.

Keep us posted if you need further assistance fixing the beginning balance issues in QBO. Community space is here 24/7. Have a good one.